Package org.apache.druid.segment.projections

Interface ProjectionSchema

All Known Subinterfaces:

BaseTableProjectionSchema

All Known Implementing Classes:

AggregateProjectionSchema, RollupTableProjectionSchema, TableProjectionSchema

public interface ProjectionSchema

Internal JSON representation of the contents of a projection for a segment ProjectionMetadata to embed within segment files. The word 'schema' is used very loosely here, as the contents of this object are not complete, and must be combined with additional metadata from the segment for most uses. While this object will contain things like the list of column names and how they are ordered, type information is not available, and in practice comes from the ColumnDescriptor declarations which define how to read the column data. For V10 segment format SegmentFileMetadata

Method Summary

Modifier and Type	Method	Description
List<String>	getColumnNames()
Granularity	getEffectiveGranularity()	If getTimeColumnName() references a column in getVirtualColumns() which is a time_floor expression, this method translates it into a Granularity.
String	getName()
List<OrderBy>	getOrdering()	Projection sort order
List<OrderBy>	getOrderingWithTimeColumnSubstitution()	Projection sort order with getTimeColumnName() substituted with ColumnHolder.TIME_COLUMN_NAME
String	getTimeColumnName()
int	getTimeColumnPosition()	The position of the time column in the column list
VirtualColumns	getVirtualColumns()

Method Details

getName

String getName()

getColumnNames

List<String> getColumnNames()

getVirtualColumns

VirtualColumns getVirtualColumns()

getTimeColumnName

@Nullable
String getTimeColumnName()

getTimeColumnPosition

int getTimeColumnPosition()

The position of the time column in the column list

getEffectiveGranularity

Granularity getEffectiveGranularity()

If getTimeColumnName() references a column in getVirtualColumns() which is a time_floor expression, this method translates it into a Granularity.

getOrdering

List<OrderBy> getOrdering()

Projection sort order

getOrderingWithTimeColumnSubstitution

List<OrderBy> getOrderingWithTimeColumnSubstitution()

Projection sort order with getTimeColumnName() substituted with ColumnHolder.TIME_COLUMN_NAME